1. Field of the Invention
The present invention relates to particle beam systems suitable for particle beam therapy using such an ionized particle beam (ion beam) as of protons or heavy ions. More particularly, the invention is directed to a particle beam system that accelerates and extracts an ion beam using a synchrotron accelerator, and to a method of generating operation control pattern data used to control devices constituting the synchrotron accelerator.
2. Description of the Related Art
Particle beam therapy, a treatment performed upon the cancer in a patient by irradiating the affected region with such an ion beam as of protons or heavy ions, is known as radiation therapy for cancer. Useable methods for ion beam irradiation include such a scanning irradiation method that is disclosed in REVIEW OF SCIENTIFIC INSTRUMENTS, VOLUME 64, NUMBER 8 (AUGUST 1993), pp. 2074-2093 (hereinafter referred to as Non-Patent Document 1).
In addition, examples of a control method which realizes within a short time the beam energy level change control required in a scanning irradiation method when a synchrotron accelerator is employed as an ionized particle accelerator, include such multi-energy extraction that realizes irradiation of an ion beam of a plurality of energy levels within one operating cycle of an ion synchrotron accelerator, which is disclosed in JP-4873563-B and JP-2011-124149-A as well as Nuclear Instruments and Methods in Physics Research, A624 (2010), pp. 33-38 (hereinafter referred to as Non-Patent Document 2). Unlike the multi-energy extraction, single-energy extraction that realizes irradiation of an ion beam of a single energy level is achieved within one operating cycle of the ion synchrotron accelerator.